In public audio presentation, e.g. an acoustic advertisement in a supermarket, it is desirable that the playback loudness is continuously adapted to the background (noise) loudness. Such adaptation of the playback volume requires a continuous measurement of the loudness somewhere within the sound exposure area, whereby the measured signal is a summation of the source signal convolved with the transfer function of the loudspeaker, the source signal convolved with the room impulse response, and the background noise, as depicted in FIG. 1. To achieve a correct estimation of the background noise, signal processing is required, e.g. echo cancellation technology with respect to the source signal.
In particular, achieving a comfortable playback volume in public presentation requires the measurement of the background noise and the measurement of the presentation set (i.e. loudspeaker) loudness, i.e. the ‘own’ loudness.